Michael Roth Says There Is No Need for Ad Holding Company to Do a Deal

Interpublic Group of Cos. Chief Executive Michael Roth says he consulted outside professionals about the company's vulnerability to an activist investor, concluding that there was no logic for an activist to try to buy into the ad giant's stock.

"Activists take position when management or the board are not doing things to maximize shareholder value," Mr. Roth said in an interview during the Cannes Lions ad festival....